/Engine/Source/Editor/MaterialEditor/Public/MaterialEditingLibrary.h
Connect a material expression output to one of the material property inputs (e.g. diffuse color, opacity etc)
static bool ConnectMaterialProperty ( [UMaterialExpression](API\Runtime\Engine\Materials\UMaterialExpression) * FromExpression, [FString](API\Runtime\Core\Containers\FString) FromOutputName, EMaterialProperty Property )